With the emergence of Industry 4.0, digitalization and intelligent manufacturing are vital to ensure competitivity, especially for manufacturers reliant on legacy machines. Upgrading legacy machines with cyber physical technology under Industry 4.0 frameworks can enable connection of these machines to existing IoT networks to allow the sharing and exchange of production information. In this paper, a legacy machine used in sheet metal folding operations is upgraded by integrating switch sensors which provide detailed data on the machine status to stakeholders, enabling in-depth analysis of the production activity before and after the implementation of lean manufacturing methods. Furthermore, it is shown that the data collected can be applied to conduct dynamic value stream mapping (DVSM) in near real time to provide deeper level insight into manufacturing processes. More detailed mapping enables identification of wastes involved with labour and design. Therefore, an innovative graphical technique is proposed to improve the flattened pattern to reduce manual handling and ease bottlenecks identified by VSM. From the collected VSM data, a leanness measure was established to provide objective and quantitative evaluation of the process performance.